Light having a wavelength in a particular visible blue range or ultraviolet range is potentially harmful to an individual's eye, though barely, or not, visible to him/her.
Hence, most individuals evaluate poorly their eye protective needs against such blue and/or ultraviolet radiations.
In particular, when selecting a lens to be used in eyeglasses, by testing several kinds of lenses, a non-specialist individual barely takes into account optical protection features of these lenses e.g. lens features related to optical transmission and/or reflection of blue/ultraviolet light, all the more these features are not, or only faintly perceptible directly.